Sadly there are 250 million children in the world without parents children. Whose lives can be changed -- the love of adults willing to step in and care for them. In Hollywood Angelina Jolie and Madonna have famously built their families -- more than their own biology. But super star Jane Fonda shows us that some of the most inspiring story -- the ones we've never hurt. ABC's juju Chang reports. The. She's Hollywood royalty who went from Bob of boom and Barbara Allen. To -- office -- in nine to five. I think I should stay in the office and get to know the routine On Golden Pond she got to act opposite her Oscar winning father. She went on to earn two Oscars herself and is still working playing a monster and touched me. Two -- -- she was known for her radical politics then evolved into an exercise empress. Then married -- billionaire media mogul but if you think you know all there is to know about Jane Fonda. You may be wrong in addition to her two biological children it turns out. The woman whose lives so much for life in public has a very private story. This is Jane Fonda's other daughter -- the never officially adopted. Her name is Mary Williams. Last time we walked as a first time market since the surgery again. There's is -- complicated mother daughter relationship one that began as a friendship. One that Mary Williams lays out in her new memoir the lost daughter. The 21 met at a summer camp in Santa Barbara California she was striking -- product that she's beautiful and also. She had this bubbly personality. Mary grew up poor in Oakland California. Her family belonged to the black Panthers. Politically active but in such a tough neighborhood -- eventually began to swallow her up a victim of sexual assaults at fourteen. This -- -- he's a Smart person but she was failing you know she wasn't. Xu -- Ling -- -- sure nobody could come near heard there were clear signs of trauma I said if you bring your grades up at the by the end of the year. And your mother permits -- make sure that you go to school in Santa Monica and live with us I literally felt like I was dying I really did. And when I sought an opportunity. I -- and I ran for it. The inner city kid from Oakland took the lifeline and suddenly found herself living in a beautiful home in Santa Monica the child of the screen -- Culture shock. -- no idea at the time I was gonna end up married to Ted Turner and my black -- was gonna end up sitting at a table in the southern plantation. You know being served by black and the only black person at the table Mary was a quick study -- her old family's values with her new ones. In her book she eloquently explains how these vastly different worlds -- not so dissimilar after all. The black Panthers the fondness and the Turner's are as different as families can be. But they all had one crucial thing in common they were not shy about acting on their political beliefs. For them the highest form of patriotism was descent. All in the spirit of trying to make the world a better place but Mary could never shed her tortured past and it was threatening her present mother daughter relationship. I was slowly realized -- was -- myself from people and the fact that I did it to the -- -- -- the most in the whole wide world. And you realize I was really crisis she just said the person I love lost -- -- one. -- -- the catalyst. That. It. What makes -- emotional -- Law. -- mean is there anything else that matters it. Mary threw herself into work helping others she taught English and worked for the UN and Morocco. She lent a hand in world Tanzania helped during the relocation of hundreds of gospel -- from the Sudan. Hiked the Appalachian trail biked across the US. Even conducted research in Antarctica. Conquering her fierce but also running away. She was running away from the anger she felt towards a biological mother and Jane was by her side when she went in search for birth mom. It was a wild experience the three of us went to -- and you know me quite privileged movie star and this woman who's had a really rough life she didn't seem to be angry she didn't seem to be resentful. She's a good sense of humor. I found out where marriage answer it. Her laugh is it an overstatement to say that came on to -- killer. It is not in a statement now. She doesn't know how -- may think she hasn't been banning -- that we're Nightline I'm juju Chang in Hollywood California. Lovely Mary Williams -- book the lost daughter went on sale today.

This transcript has been automatically generated and may not be 100% accurate.

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